Brush making

Abstract

A process for forming a grooming implement is provided. The steps include providing a blank having a head and a handle, wherein the head has one or more void spaces which divide said head into at least two segments, and injecting an elastomer into the void space at a temperature of at least about 245° C. thereby fusing the elastomer to the segments and forming a resiliently flexible joint. The elastomer is the sole mechanical link between the segments such that the segments can flex relative to each other and the elastomer can be stretched to about 120% of its unstressed length without separation of the elastomer from the segments.

What is claimed is:  
     
       1. A process for forming a grooming implement, comprising the steps of: 
       i) providing a blank comprising a plastic material and having a head and a handle, wherein said head has one or more void spaces which divide said head into at least two segments;  
       ii) injecting an elastomer having a modulus of elasticity of less than 500 MPa into said void space at a final injection point at a temperature of at least about 245° C. thereby fusing said elastomer to said segments and forming a resiliently flexible joint, wherein said elastomer is the sole mechanical link between said segments such that said segments can flex relative to each other; and  
       iii) where said elastomer can be stretched to at least about 120% of its unstressed length without separation of said elastomer from said segments.  
     
     
       2. The process of  claim 1 , wherein the grooming implement is a toothbrush. 
     
     
       3. The process of  claim 1 , wherein said elastomer can be stretched to about 150% of its unstressed length without separation of said elastomer from said segments. 
     
     
       4. The process of  claim 1 , wherein said elastomer can be stretched to about 200% of its unstressed length without separation of said elastomer from said segments. 
     
     
       5. The process of  claim 1 , wherein said elastomer is injected at temperature between about 245° C. and about 270° C. 
     
     
       6. The process of  claim 1 , wherein said elastomer is a polyolefin. 
     
     
       7. The process of  claim 6 , wherein said polyolefin is a styrene-ethylene-butylene-styrene elastomer. 
     
     
       8. The process of  claim 1 , wherein said at least two segments are formed from polypropylene. 
     
     
       9. The process of  claim 1 , wherein said head comprises two bands of said elastomer. 
     
     
       10. The process of  claim 1 , wherein said elastomer forms a non-linear band. 
     
     
       11. The process of  claim 1 , wherein said elastomer forms a band and wherein the interfacial walls of said band are substantially perpendicular to a face of said head. 
     
     
       12. The process of  claim 11 , wherein said face is a top face. 
     
     
       13. The process of  claim 1 , wherein said elastomer detaches over less than about 5% of the connected interfacial area between said elastomer and said segments when said elastomer is stretched to at least about 120% of its unstressed length. 
     
     
       14. The process of  claim 1 , wherein said elastomer is injected by an injection molding apparatus having a cylinder and a cylinder nozzle and the temperature in said cylinder is between about 210° C. and about 220° C. 
     
     
       15. The process of  claim 14 , wherein said injection molding apparatus further comprises a hot runner disposed between said cylinder nozzle and said final injection point, wherein said elastomer is heated to said temperature of at least about 245° C. by said hot runner. 
     
     
       16. A process for forming a toothbrush, comprising the steps of: 
       i) providing a blank comprising a plastic material and having a head and a handle, wherein said head has one or more void spaces which divide said head into at least two segments;  
       ii) injecting an elastomer having a modulus of elasticity of less than 500 MPa into said void space at a final injection point at a temperature of at least about 245° C. thereby fusing said elastomer to said segments and forming a resiliently flexible joint, wherein said elastomer is the sole mechanical link between said segments such that said segments can flex relative to each other; and  
       iii) wherein said elastomer can be stretched to at least about 120% of its unstressed length without separation of said elastomer from said segments and wherein said elastomer detaches over less than about 5% of the connected interfacial area between said elastomer and said segments when said elastomer is stretched to said at least about 120% of its unstressed length.  
     
     
       17. The process of  claim 16 , wherein said elastomer can be stretched to about 150% of its unstressed length without separation of said elastomer from said segments. 
     
     
       18. The process of  claim 1 , wherein said elastomer can be stretched to about 200% of its unstressed length without separation of said elastomer from said segments. 
     
     
       19. The process of  claim 1 , wherein said elastomer is injected at temperature between about 245° C. and about 270° C. 
     
     
       20. The process of  claim 19 , wherein said elastomer is a polyolefin. 
     
     
       21. The process of  claim 1 , wherein said elastomer forms a band and wherein the interfacial walls of said band are substantially perpendicular to a face of said head. 
     
     
       22. The process of  claim 21 , wherein said face is a top face. 
     
     
       23. The process of  claim 16 , wherein said elastomer is injected by an injection molding apparatus having a cylinder and a cylinder nozzle and the temperature in said cylinder is between about 210° C. and about 220° C. 
     
     
       24. The process of  claim 23 , wherein said injection molding apparatus further comprises a hot runner disposed between said cylinder nozzle and said final injection point, wherein said elastomer is heated to said temperature of at least about 245° C. by said hot runner. 
     
     
       25. The process of  claim 1 , wherein said elastomer can be stretched to said 120% of its unstressed length for at least 10,000 extension-relaxation cycles without separation of said elastomer from said segments. 
     
     
       26. The process of  claim 25 , wherein said elastomer can be stretched to 200% of its unstressed length for at least 25,000 extension-relaxation cycles without separation of said elastomer from said segments. 
     
     
       27. The process of  claim 16 , wherein said elastomer can be stretched to said 120% of its unstressed length for at least 10,000 extension-relaxation cycles without separation of said elastomer from said segments. 
     
     
       28. The process of  claim 27 , wherein said elastomer can be stretched to 200% of its unstressed length for at least 25,000 extension-relaxation cycles without separation of said elastomer from said segments.